Furnace and heating repair in Fort Belvoir.

Winter on this stretch of the Potomac is short on paper. Reagan National Airport, about 13 miles up the river, averages a January low near 30 and about 60 freezing nights a year, with the median first freeze on November 18 and the last on March 24. The cold snaps are what catch a furnace out: an Arctic front on December 23 and 24, 2022 dropped wind chills to around 5 below near the tidal Potomac, and late January 2026 brought over a week of Arctic air, with Extreme Cold Warnings on the 27th, 30th and 31st.

Off post, most houses are Cook Inlet’s 256, and Fairfax County’s parcel records show every one with gas connected and a full basement, almost all built from 2002 through 2004: a gas furnace downstairs, often the builder’s. After twenty-some winters, a long cold run takes out what lights and proves the flame: an igniter, $240 to $410 replaced, or a flame sensor glazed until the burners light and drop out, cleaned for $95 to $180.

If your furnace vents through two white plastic pipes in a wall, watch them after a snow. The January 2016 blizzard left 23 to 31 inches across Fairfax County, and a drift over those pipes shuts a high-efficiency furnace down with nothing broken. Clear both and reset the thermostat.

Accotink is different. The county shows no gas available to nearly every Backlick Road lot, so the systems we repair there are heat pumps and propane furnaces. In a winter this mild a heat pump carries most of the load, and its backup strips should only kick in during a real cold snap; strips running all day mean it isn’t keeping up. On post, family housing heat, central or geothermal, is The Villages at Belvoir’s to maintain, so residents call its maintenance team, not us.